Welcome to HVAC-Talk.com, a non-DIY site and the ultimate Source for HVAC Information & Knowledge Sharing for the industry professional! Here you can join over 150,000 HVAC Professionals & enthusiasts from around the world discussing all things related to HVAC/R. You are currently viewing as a NON-REGISTERED guest which gives you limited access to view discussions

To gain full access to our forums you must register; for a free account. As a registered Guest you will be able to:

Participate in over 40 different forums and search/browse from nearly 3 million posts.

it's not pressure, it's sat temp !!

Originally posted by thewoodman I have an ongoing argument with my boss about reading the gauges. I say the green scale for R22 tells me the saturation temp. of the refrigerant. He says it is the actual temperature of the freon in the suction line. I say no it is the temperature at which the freon saturates at the corresponding pressure. Pressure temperature relationship. Ok.. he tells me he as two years of AC college and I can't convince him different. He still maintains it is the temperature of the freon. AM I not understanding this or what??

Like most, your "boss" attended school but either missed the point or was taught by an "experienced" instructor who de-emphasized such topics in the interests of being "practical".

Unless you are deriving compression ratio or setting pressure controls accurately then the only useful information on the gauge is the sat temp (even more true when you work with several refrigerants).

Most of the heat absorbed in the evaporator, and rejected in the condenser are latent exchanges so the respective sat temp represents the temp at witch the refrigerant is exchanging heat. This is mucho impport-o.

I do get pissed every time someone makes reference to head or suction pressure because they are missing this major point. The top techs out there will not flame this thread and they are all nodding right now.

<snip>
He says it is the actual temperature of the freon in the suction line.
</snip>
1. Because of what I said, it is very close to the actual temp of the refrigerant at saturation *inside the evap coil* before super heating occurs.
2. If it was the actual temperature of the freon **in the suction line**, this would only be true if the saturation point extended out side the evaporator (i.e. liquid flood back) and into the suction line which is bad ju ju.

If the state exams where worth a crap your "boss" would not have the license and perhaps you would (other real qualifications permitting). You could then bust him down to installer until he learned something (two years of AC college notwithstanding).

I have not fully discussed the subject here. It is also possible that your "boss" understands it better than your question indicated but has failed to communicate the distinction between suction line and evaporator.

everyones input is great. All advice is good. Thanks guys. I don't think I will tell him he is wrong. But I don't think he understands what superheat is either. I tried to explain this by using water as an example and his reply was water is different than freon. He still uses his hand to feel for the suction line to determine if it is correctly charged. I believe in using a pt chart with the units mfg. suggestion. Again many thanks.

Like most incumbent bureaucrats and enforcement agencies, there is no requirement to be right when you are in charge.

keep learning, do not listen to opinion, conjecture, or misinformation, pursue hard facts, go into business for your self, compete away your previous employers market share, laugh at him while he's greeting you on the way into Wal-Mart.

soap box

<snip>
Are we not supposed to change topic within a thread?
Guess I never realized that was against the house rules?
Guess I should read the rules. lol
</snip>

Glad to see your worried about the important stuff.

My concern is that this board is becoming too PC and regulated, so I guess it reflects our industry and national problems as well.

Don't get me wrong, I'm a nice guy. I just enjoy a spirited argument w/o sensitivity usually in pursuit of technical truth. Politics and opinion fights are usually a waste of time, but it is Saturday. LOL

No, arguments are... and since I know you work out every minute of the day and are so much darn bigger than most of us here, I was saving you a trip to the computer store to purchase another keyboard .......

Ya know I am just kidding. I use that to break up a what ever before a what ever can develop.

Originally posted by mdman
My concern is that this board is becoming too PC and regulated, so I guess it reflects our industry and national problems as well.

Don't get me wrong, I'm a nice guy. I just enjoy a spirited argument w/o sensitivity usually in pursuit of technical truth. Politics and opinion fights are usually a waste of time, but it is Saturday. LOL

Actually... One of the reasons for their being Associates is so there be less disorder and more flow. Asking the new people to follow guidelines and getting the older members to help us out is not so easy while trying to read 1500 or more posts a day. Remember, I am a professional working member too.

I think that everyone here should be an Associate for a week and seriously do the job for a week. Most will change their attitudes about this site and how it is run to a more positive. They will want it run so everyone will have fun and have it be helpful at the same time.